Synthesis of cellulose by Acetobacter xylinum. 3. Substrates and inhibitors

Abstract

STRUCTURE OF SERRATAMIC ACID 669 obtained was applied to a paper along with L-serine and authentic a-alanine and the chromatogram run in 80% phenol. Development with ninhydrin showed the product to have the same RF value as a-a]anine. 2:3-Epoxydecanoic acid. Freshly distilled octyl aldehyde (5.7 g.) and ethyl chloroacetate (5.5 g.) in dry ether (100 ml.) were added to sodium methoxide (from 10 g. of Na) suspended in dry ether. After standing for 48 hr. at room temp. water was added, and the ether layer was separated and dried over anhydrous Na2SO4. The oil left after removal of the solvent was purified by vacuum distillation, yielding ethyl 2:3-epoxydecanoate (6 g., b.p. 90-93o/0.1 mm.). Saponification rapidly occurred on the addition of an excess of 12% (w/v) KOH in methanol at room temp., with the * Part 2: Hestrin & Schramm (1954). For a preliminary communication on someexperimentsdescribedinthepresent paper and results obtained in a tracer analysis of cellulose production, see Schramm, Gromet & Hestrin (1957).

Cellulose production by Acetobacter acetigenum in defined medium

“…The equal yields obtained from the three adjuncts, when used at concentrations equivalent to 0-1-0.2 % (wlv) adjunct carbon, suggests that they act in stimulating cellulose synthesis by the same mechanism, presumably a preferential oxidation of the adjunct to spare the glucose substrate for cellulose synthesis. This is supported by the recent observation of Schramm, Gromet & Hestrin (1957) that acetate, citrate, succinate and other intermediates of the tricarboxylic acid cycle are all readily oxidized to CO, by washed suspensions of A. xytiwm. The buffering action of these adjuncts must also be an important additional factor in producing high cellulose yields by maintaining the cultural pH value within the optimum range for cellulose synthesis.…”

Cyclic diguanylic acid and cellulose synthesis in Agrobacterium tumefaciens

“…Furthermore, the two organisms markedly differ with respect to the efficiency of cellulose synthesis in terms of the molar ratio cellulose monomer to glucose oxidized to C02, which reflects the relationship between the polymerization process and overall cellular energy metabolism. In resting cells of A. tumefaciens, this ratio is rather low (0.03) compared with A. xylinum, which under similar conditions exhibits an efficiency ratio significantly greater than unity (18,22).…”

“…The supematant comprises the unwashed membranes. This fraction was recentrifuged at 18,000 x g for 20 min. The resultant pellet resuspended in TME buffer comprises the washed membranes, typically containing 5 to 6 mg of protein per ml.…”

The Importance of TCA Cycle Related Acids in Bacterial Cellulose Production

“…These intermediate acids in the TCA cycle have been extensively studied with respect to the respiration of bacteria [10,11,12]. The glucose added as a carbon source is phosphorylated to glucose-6-P which is partly converted into cellulose directly, but the considerable amount of it undergoes the oxidative dissimilation via pentose cycle or citrate cycle, the pentose cycle is dominant [13], to generate the energy as ATP, NADH, NADPH etc.…”